Fire detector



March 7, 196 1 H. c. SMITH 2,974,210

FIRE DETECTOR Filed July 9, 1959 Harvey G. Smith INVENTOR.

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United States Patent .0

FIRE. DETECTOR Harvey C. Smith, 34160 W. Bordman, Memphis, Mich.

Filed July 9, 1959, Ser. No. 826,071

3 Claims. (Cl. 200-142) 4 This invention relates generally to fire alarm systems, and more particularly to a novel fire detection switch adapted to be utilized in connection with various fire alarm systems for detecting and indicating fire.

Many millions of dollars and lives are lost annually due to fire. Although most modern buildings are equipped with alarm systems for detecting and indicating fire and sprinkler systems for controlling the fire, many older buildings are still in existence which have no fire detection or controlling means whatsoever. Most of these buildings are without fire protection means because the means presently available are expensive to purchase and install. Accordingly, if an inexpensive and efficient detection and alarm system is developed, millions of dollars and many lives could be saved annually.

Accordingly, it is the principal object of this invention to provide a novel fire detection switch which may be utilized in any of a plurality of fire alarm systems for initially detectinga fire and, secondly, alarming the inhabitants of the building of the detected fire.

It is a further object of this invention to provide a novel fire detection switch which may be manufactured at a low cost such that a plurality'of switches may be utilized in a building. It is contemplated that the switches be electrically connected in parallel and arranged between a source of electrical energy and an alarm, such as a bell or the like, to detect and advise of the fire.

It is a still further object of this invention to provide a novel fire detection switch wherein a closed container containing a pool of conductive liquid is provided. The container has a pair-ofspaced contacts which maybe bridged by the pool when the container is in a particular pivoted position. Spring bias means are associated with the container for pivoting the container to a position wherein the contacts are normally bridged. Fuse means are provided which act on the container in opposition to the spring bias means" for retaining the container in a position such that the pool of conductive liquid is remote from the contacts. If there is a fire or intense heat in the building wherein the switch is located, the fuse means, including a link fuse, will become severed so as to allow the spring bias means to carry the container to a pivoted position wherein the contacts are bridged and the alarm circuit is energized.

These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective view of the switch particularly illustrating the casing;

Figure 2 is a vertical sectional view taken substantially along the plane 22 of Figure 1;

Figure 3 is a vertical sectional view taken substantially along the plane 33 of Figure 1;

2,974,210 Patented Mar. 7, 1961 Figure 4 is a horizontal sectional view taken substan tially along the plane 4-4 of Figure 3; and

Figure 5 is a diagrammatic circuit diagram illustrating an exemplary utilization of the novel switch construction.

With continuing reference to the drawings, the numeral 10 generally represents the switch construction including a flat base 12 and a casing 14 perforated at 16, having an encircling flange 18 adapted to mate with the base 12 to receive screws 20 therethrough to secure the switch 10 to a supporting surface, as 22.

Enclosed between the base 12 and casing 14 is the heart or operating mechanism of the switch construction. Initially, a pair of angle members 24 and 26 are secured to the base 12. The angle members are spaced from each other as clearly illustrated in Figures 2 and 4. The upstanding legs of the angle members 24 and 26 have apertures therein which rotatably receive opposed spindles 28 and 30 respectively. The spindles 28 and 30 are terminally bifurcated, as is best illustrated in Figure 4, and receive a disk 32 in the opposed bifurcations. The disk 32 defines a central aperture 34 therein through which a cylindrical container 36 extends. The container 36 is secured to the apertured disk 32. Within the container 36 is received a pool of conductive liquid 38. Also, a pair of spaced contacts 40 and 42 are supported within the container 36 and in turn are electrically connected to conductors 44 and 46 respectively which extend exteriorly of the casing 14 through an opening 48 provided.

The spindle 28 has a square end 50 which projects beyond the support member 24. A V-shaped member 52 has a pair of arms 54 and 56. A square opening 58 is formed in the V-shaped member 52 adjacent the vertex thereof. The square opening 58 receives the square end 50 of spindle 28. Accordingly, it should be apparent that upon rotating the V-shaped member 52 about its vertex, the square end 50 of the spindle 28 will also be rotated. Accordingly, the spindle 28, disk 32, and spindle 30 will also be rotated. Since the disk 32 carries with it the container 36, the pool of conductive liquid 38 may be in a position to bridge the contacts 40 and 42 or may be disposed remote therefrom.

The leg 54 of V-shaped member 52 has a notch 60 formed therein, while the leg 56 of V-shaped member 52 has a notch 62 formed therein. A pair of eyes 64 and 66 are secured to the base 12 as particularly indicated in Figure 3. Secured between the notch 60 on leg 54 and the eye 64 is a link fuse 68. Secured between the notch 62 on leg 56 and the eye 66 is a spring'70. The spring 70 tends to pivotally urge the V-shaped member 52 to rotate about its vertex in a clockwise direction so as to turn the spindles 28 and 30 and disk 32 clockwise to carry the pool of conductive liquid 38 into bridging relationship with contacts 40 and 42. The link fuse 68 counteracts the spring urging of spring 70 to retain the container 36 in a substantially horizontal position wherein the pool of conductive liquid 38 lies remote from the contacts 40 and 42.

Accordingly, it is thought that the structure and operation of the switch 10 should be well understood. The ambient temperature permeates the casing 14 through the perforations 16. When the temperature is high enough, the link fuse 68 will sever so as to allow the spring 70 to pivot the V-shaped member 52 clockwise, to in turn pivot the container 36 clockwise to bridge the contacts 40 and 42. If the switch 10 be utilized in an alarm system as illustrated in Figure 5, an alarm will be energized to advise inhabitants of a building or such of the fire. In Figure 5, it will be noted that an electrical energy source as a battery is serially connected with a plurality of parallel connected switches 10 to a relay coil 82 which controls normally open switch 84. Accordingly, when the link fuse 68 severs due to the ambient temperature,

the spring 70 will pivot the V-shaped member 52 clockwise to pivot the container 36 to electrically bridge the contacts 40 and 42. With the contacts 40 and 42 bridged, the relay coil 82 will be energized to close the normally open switch 84. The switch 84 is electrically connected in series with an electrical energy source, generally designated as 86, and a plurality of alarm devices which may be in the form of a bell 88, hornv 90, or light 92.

From the foregoing, it will be appreciated that a simple fire detection switch construction has been disclosed wherein a link fuse may be severed due to ambient ternperature and accordingly allow a pool of conductive liquid to bridge a pair of normally open electrical contacts to energize an alarm device.

The foregoing is considered as illustrative onlyof the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it, is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all, suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A fire detection. switch comprising a pivotally mounted closed container, a pool of conductive fluid in said, container, a pair of spaced contacts in said container adapted to be bridged by said pool, spring bias means pivotally urging said container into a pivoted position such that said pool bridges said contacts, and fuse means acting on said container, opposed to said spring bias means, for retaining said container in a position such that said pool is remote from said contacts, a base portion, a pair of spaced support members extending upwardly therefrom, opposed spindles rotatably mounted in said, support members, means securing said container to said spindle, one. of said spindles having a square end portion, a, V-shaped member defining a square opening,

proximate the vertex thereof, said square opening receiving said end portion, said V-shaped member having a first leg and a second leg, said fuse means including a link fuse secured between saidfirst leg and said base, said spring bias means including a spring secured between said second leg andsaid base.

2. A fire detection switch comprising a pivotally mounted closed container, a pool, of conductive fiuid in said container, a pair of spaced contacts in said container adapted to be. bridged by said pool, spring bias meanspivotally urging said container into a pivoted position means, for retaining said container-in a position such that said pool is remote from said contacts, a base portion, a pair of spaced support members extending upwardly therefrom, opposed spindles rotatably mounted in said support members, said spindles being terminally bifurcated and having a disk secured therebetween, a

central aperture in said disk, said container extending through said aperture and secured to said disk, one of said spindles having a square end portion, a V-shaped member defining a square opening proximate the vertex thereof, said square opening receiving said end portion,

said V-shaped member having a first leg and a second such that said pool bridges said contacts, and fuse means acting on said container, opposed to said spring bias means, for retaining said container in, a position such that said pool is remote from said contacts, a base portion, a pair of spaced support members extending upwardly therefrom, opposed spindles rotatably mounted in said support members, said spindles being terminally bifurcated and having a disk secured therebetween, a

central, aperture in said. disk, said container extending through said aperture and secured to said disk, one of said spindles having a square end portion, a V-shaped member defining a square opening proximate the vertex thereof, said square opening, receiving said end portion, said V-shaped member having a first leg and a second leg, said fuse means including a link fuse secured between said first leg and said base,,said spring bias means including a spring secured between said second leg and said base, and a perforated casing secured to said base enclosing said container, fuse means and spring bias means for exposing said link fuse to ambient temperature.

References Cited in the file of this patent UNITED STATES PATENTS 1,176,809 

